The invention is related to the field of thermal infrared detectors, and in particular to thermal infrared detectors having infrared (IR) pixel designs that utilize thermo-optic effect to detect thermal radiation.
Thermal infrared detectors basically work by measuring temperature changes induced by incident infrared radiation (especially mid-IR to far-IR wavelength in the range of 2-25 μm). A number of physical quantities that show temperature dependence have been quantified for infrared detection and have been realized in focal plane array designs. Such examples include electrical resistance (vanadium oxide, amorphous silicon or polycrystalline germanium bolometers), pyroelectric effect (pyroelectric pile) and thermal expansion (thermal bimorph). Despite the variety of detection mechanisms, a typical thermal detector pixel is comprised of two components—the infrared absorption part which absorbs incident radiation; and the transduction part that converts the temperature change resulting from absorbed light into a measurable physical quantity that can be read out and processed.